Picture frame



y 1968 L. D. SIEGLER 3,394,479

P ICTURE FRAME Filed April 22, 1966 2 Sheets-Sheet 1 .INVENTOR Lawrence D. Snegler July 30, 1968 5| 3,394,479

PICTURE FRAME Filed April 22, 1966 2 Sheets-Sheet 2 55 Lawrence D. Siegler United States Patent 3,394,479 PICTURE FRAME Lawrence D. Siegler, 2965 Randy, Farmers Branch, Tex. 75234 Filed Apr. 22, 1966, Ser. No. 544,503 Claims. (Cl. 40-154) ABSTRACT OF THE DISCLOSURE A picture frame formed of cardboard and the like and having four frame units interconnected at the corner of the frame.

This invention relates to display devices and more particularly relates to picture frames.

It is an object of the invention to provide a new and improved picture frame.

It is a still further object of the invention to provide a picture frame formed of light-weight flexible sheet material such as paperboard.

It is another object of the invention to provide a picture frame having curved front panels which are adapted to fold flat when the frame is disassembled.

It is another object of the invention to provide a picture frame having front panels which have flat planar surfaces when the frame is disassembled and which assume a predetermined curvature when the frame is assembled.

It is another object of the invention to provide a picture frame formed of light-weight flexible sheet material and having simulated mitred joints at the corner connections between the several frame units forming the frame, such joints being formed in such a manner as to eliminate the difficult problems of alignment of thin edge surfaces inherent in a mitred joint.

It is still another object of the invention to provide a picture frame having a plurality of frame units connected together by simulated mitred joints formed by a front panel of one frame unit overlapping the front panel of an adjoining connected frame unit, the overlapping panel having an end edge out along a line bisecting the angle of juncture between the frame units.

It is another object of the invention to provide a picture frame of relatively thin flexible sheet material having simulated mitred joints wherein a front panel of one frame unit overlaps a front panel of an adjacent connected frame unit and each overlapped front panel has an end edge surface engaging an inside panel surface of the connected frame unit to enhance the structural rigidity of the joint in and aid in holding it at the proper angle of juncture.

It is another object of the invention to provide a picture frame having a plurality of frame units each of which comprises a front panel, a side panel joined along a front edge thereof with an outside edge of the front panel, a first back panel extending between the inside edge of the front panel and the side panel, and a second back panel spaced from and parallel to the first back panel, adjacent ends of the frame units having mating end edge surfaces for providing a simulated mitred joint between the frame units including one front panel extending in overlapping relationship on the adjacent front panel and having an end edge surface formed at an angle to provide the appearance of a mitred joint at the front of such frame while the overlapped portion of the frame unit end sections engage inside surfaces of the overlapping frame unit sections for improving the structural rigidity of the joint.

It is still a further object of the invention to provide a picture frame comprising a plurality of frame units "ice each formed independently and secured together by simulated mitred joints.

It is a still further object of the invention to provide a blank form which may be stamped from relatively thin flexible sheet material, folded, and cemented to form a multi-sided picture frame provided with simulated mitred joints.

It is a further object of the invention to provide a partially assembled picture frame of relatively thin flexible sheet material which is permanently cemented over certain panel areas and provided with a self-sticking adhesive over other panel areas whereby the components of the frame are folded to a substantially flat condition and subsequently unfolded and locked in assembled condition by bringing together the areas coated with the selfsticking adhesive.

It is another object of the invention to provide a picture frame comprising a plurality of frame units connected together with simulated mitred joints, each of the units having a front panel, a side panel connected along a front edge with the front panel, a first back panel secured along an inside edge with the inside edge of the front panel, a second back panel secured along an outside edge with a back edge of the side panel, and the back panels :are cemented together in laminated relationship while at each simulated mitred joint one front panel overlaps an adjacent front panel and is provided with an end edge formed at an angle along a line bisecting the angle of juncture between the frame units, the overlapping panel portion resting in closed laminated or layer relationship with the overlapped front panel providing a simulated mitred joint.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURE 1 is a front view in elevation of a picture frame embodying the invention;

FIGURE 2 is a fragmentary view in section along the line 2-2 of FIGURE 1;

FIGURE 3 is :an enlarged fragmentary front view in elevation of connecting end sections of a pair of adjacent frame units of the frame of FIGURE 1 at an intermediate stage in the assembly of the frame;

FIGURE 4 is an enlarged fragmentary view in elevation showing the adjacent end sections of the frame units of FIGURE 3 in their assembled relationship;

FIGURE 5 is a fragmentary back view in elevation of the adjacent frame unit end sections of FIGURE 3 at the same intermediate stage in the assembly of the frame;

FIGURE 6 is a fragmentary back view in elevation of the assembled adjacent end sections of the frame shown in FIGURE 4;

FIGURE 7 is a fragmentary view in perspective of the adjoined frame unit end sections shown in FIGURES 4 and 6 illustrating insertion of a picture supporting back panel in the sight window of the frame;

FIGURE 8 is a fragmentary front view in elevation of a blank for forming adjoining frame units as illustrated in FIGURES 3 through 7;

FIGURE 9 is a fragmentary back view in perspective of end sections of the connecting frame units shown in FIGURE 7;

FIGURE 10 is a fragmentary back view in perspective with a portion of the structure cut away to show a pair of spacer tabs between back panels of the frame units illustrated in FIGURES 1-9;

FIGURE 11 is a fragmentary front view in elevation of an alternative form of picture frame embodying the invention and,

FIGURE 12 is a fragmentary view in section along the line 12-12 of FIGURE 11.

Referring to FIGURES 1-10, a picture frame embodying the invention includes frame units 21, 22, 23 and 24 formed of a single planar blank of paperboard or the like. Each frame unit has a front panel 25, a side panel 30, a first back panel 31, and a second back panel 32 in parallel spaced relationship with the first back panel. The front panel 25 is hingedly secured along its outside edge with the side panel along a fold line 33 and is similarly hingedly connected with the first back panel 31 along a fold line 34 extending along what shall be defined as the inside edge of the front panel. The side panel 30 is hingedly secured along its back edge with the outside edge of the second back panel 32 along a fold line 35. A narrow longitudinal spacer strip is connected with the second back panel along the inside edge of the second back panel 32 along a fold line 41 while a longitudinal securing tab 42 is hingedly connected with the front edge of the spacer strip 40 along a fold line 43. A reinforcing inner side panel 44 is hingedly connected along its back edge to the outside edge of the first back panel along a broken fold line 45 extending between a plurality of rectangular longitudinally spaced spacer tabs provided along the back edge of the panel 44 to cooperate with the spacer strip 40 for maintaining the proper spaced parallel relationship between the first and second back panels 31 and 32. The tabs 50 are formed on the panel 44 by cutting the first back panel 31 along the longitudinal lines 50a and along the lateral lines 50b. The fold line segments 45 are then formed in the blank between the tabs so that the tabs are movable with and remain in the same plane as the panel 44 when it s bent along the fold line segments 45 relative to the first back panel 31. As best seen in FIGURE 10, the cutting of the blank to provide the tabs 50 extending from the panel 44 leaves a plurality of spaced longitudinal slots 51 of the same size as the tabs 50 along the first back panel 31 at its fold line 45. The slot 51 serve no functional purpose but rather are the byproduct of the removal of the material from the first back panel to form the tabs 50 on the panel 44.

Adjacent end edges 52 of the second back panel 32 extend at an angle such that when the back panel sections are brought together as in assembling the frame units 21 and 22, FIGURES 5 and 6, the end edges 52 become abutting or coengaging surfaces extending along a line bisecting the angle of a juncture between the second back panel surfaces. In the picture frame 20 the edges 52 are cut at 45 degree angles with the longitudinal axis of their panels since the frame is a rectangle with the frame units joining each other at 90 degree angles. The blanks for the frame units 21 and 22, FIGURE 8, are hingedly connected along a fold line 53 between the panels 30 which extends along the side corners of the frame when the frame units are joined as illustrated.

An end edge 54 of a front panel 25 in the unit 21 is in the form of a convex curve sloping from the fold line connection 33 of the front panel with its adjoining side panel 30 toward the body of the front panel, the resulting tapered end section 25a of the front panel 25 comprising an overlapping end section in the assembled relationship of the adjacent connected frame units 21 and 22 as seen in FIGURE 7. The end edge 54 then extends over the front face of the front panel of the unit 22 along a line bisecting the angle between the units to present the appearance of a mitred joint.

An end edge 55 of the first back panel 31 in the frame unit 21 connects with the curved end edge 54 of the front panel 25 extending perpendicular to the fold line 34 between the panels 25 and 31 so that when the units are assembled together as in FIGURE 7 the end edge 55 extends along the overlapped portion 34a of the fold line 34 between the front panel 25 and first back panel 31 of the frame unit 22. End edges and 61 of the front and first back panels 25 and 31, respectively, of the frame unit 22 adjacent to the frame unit 21 extend coincident with each other perpendicular to the longitudinal axes of the panels and their connecting fold line 34 joining the curved edge 54 of the unit 21 at the fold line 33 so that when the front and back panels of the frame unit 22 are in their assembled relationship end portions of the panels, FIGURE 7 extend behind in underlapping relationship with the section 25a of the adjacent front panel of the unit 21. The end edges 60 and 61 on the front and first back panels respectively of the unit 22 engage the inside face of the reinforcing side panel. 44 of the frame unit 21 appreciably enhancing the structural rigidity of the connection between the units 21 and 22.

A recess 62 is formed at the ends of the tab 42 and the spacer strip 40 on the unit 21 adjacent to the frame unit 22 so that a slot 64, FIGURE 9, is defined along the top edge 63 of the spacer strip 40 behind the front panel 25 on the unit 21 to receive joined edge sections of the front and first back panels of the unit 22 along the fold line 34 where the overlapped end sections of the panels extend behind the overlapping end section 25a of the front panel of the unit 21.

The picture frame blank which is shown in fragmentary form in FIGURE 8 preferably is a strip or blank providing forms for the frame units 21 through 24. The opposite end sections of the strip have mating end edges corresponding to the end edges of the units 21 and 22 as illustrated in FIGURE 8. Each pair of adjacent end edge surfaces of joined frame unit blanks are formed to mate as illustrated in FIGURE 8.

Each of the frame units forming the picture frame 20 is assembled by folding its blank form into the cros sectional shape shown in FIGURES 2, 7, and 9. The reinforcing side panel 44 is folded along the broken fold line 45 to a degree angle with the first back panel 31, care being exercised to insure that the spacer tabs 50 are folded out of their slots 51 in the first back panel so that they remain in the plane with the panel 44 to function as a spacer between the first back panel 31 and the second back panel 32. The blank is folded and creased along the fold line 34 with a complete reverse fold being made in the blank so that the facing surfaces of the front panel 25 and the first back panel 31 may be glued together as best seen in FIG- URE 2 securing them together in laminated relationship along longitudinal areas 25a and 31a of the panels extending along the fold line 34 to hold the front panel in the concave contour shown. The width of each panel 25 is greater than the straight line distance between the fold lines 33 and 34 when each frame unit is assembled with the side and back panels 30 and 31 in the perpendicular relationship shown in FIGURE 2. Thus, each panel 25 must assume either a convex or a concave contour. The securing of the front panel to the back panel 31 over a longitudinal area along the fold line 34 insures that the front panel is held in a concave form. The blank is folded along the fold line 33 to position the side panel 30 perpendicular to the back panel 31 so the reinforcing side panel 44 may be secured by gluing its outside face to the inside face of the side panel 30.

The blank is now folded along the fold lines 35, 41 and 43 forming the second back panel 32 along the fold line 35 at a 90 degree angle with the side panel 30 and with the spacer strip 40 being bent to a 90 degree angle along the fold line 41 with the second back panel 32. The longitudinal securing tab 42 also is bent to a 90 degree angle relative to the spacer strip 40 and is then glued along its top face to the back face of the first back panel 31 in the relationship shown in FIGURE 2. With the panels 44 and 30 secured together and the securing tab 42 cemented to the back face of the panel 31, the spacer strip 40 and the tabs 50 hold the back panels 31 and 32 in spaced parallel relationship.

After each frame unit of the picture frame 20 is folded and secured as described above, the frame units 21-24 are folded and secured into the end-to-end relationship shown in FIGURE 1 to complete the frame 20. After the folding and securing of each frame unit and prior to their being secured as shown in FIGURE 1, adjacent connected frame units, such as the frame units 21 and 22, are related as illustrated in FIGURES 3 and 5. The frame unit 22 is folded toward the frame unit 21 pivoting about the fold line 53 in the connecting side panels 30 of the frame units until the unit 22 is at a 90 degree angle with the unit 21. The end sections of the front and first back panels 25 and 31 of the unit 22 are inserted behind the front panel of the unit 21 between its front panel and its first back panel into underlapping relationship until the end edges 60 and 61 on the front and first back panels, respectively, of the frame unit 22 engage the inside face of the reinforcing side panel 44 of the unit 21. FIGURES 4 and 6 illustrate in elevation the front and back, respectively, of the two frame sections in their folded together relationship. While the front panels of the two frame units are in the over and underlapping relationship previously described, the second back panels 32 are engaged with each other along their end edge surfaces 52 forming a mitred joint and the fold line section 34a between the front and first back panels of the frame unit 22, FIGURE 7, extends along the end edge surface 55 of the first back panel of the frame unit 21. If desired an adhesive tape strip, not shown, may be placed along the back face of the adjacent back panels 32 over the seam formed by the engaging edge surfaces 52 to hold the frame units 21 and 22 in their folded together relationship.

After securing the frame units 21 and 22 together as described, the frame unit 23 is folded into engaging relationship with the frame unit 22 and the frame unit 24 is folded to the same relationship with the frame unit 23 after which the free ends of the frame units 21 and 24 are secured together in the same manner. The free ends of the units 21 and 24 are held together by an adhesive strip 26 placed on the back faces of the back panels 32, FIGURE 1, across the line of contact of the end edge surfaces 52. The strip 26 preferably extend normal to the edge surfaces 52. After the four frame units have been connected together to provide the completed rectangular frame 20 having simulated mitred corner joints, a picture supporting panel 65 is secured in the viewing window 66 defined and encompassed by the four frame units. Preferably, a picture which is to be displayed in the frame is first suitably secured on the front face of the panel 65. The panel is then inserted from the back side of the frame into the viewing window so that the edge surfaces 67 of the panel 65 extend along the inside faces of the spacer strip 40, as r illustrated in FIGURE 2, the panel 62 being cut slightly smaller than the viewing window to permit ready insertion. The laminated relationship of the front panel 25 and the first back panel 31 of each frame unit provides an inwardly extending lip section 68 which overlaps the front face of the panel 65, FIGURE 2. The panel 65 is secured to the frame by a suitable adhesive strip 70 which is secured along the back face of the back panels 32 and the picture supporting panel 65 over the seam between the picture panel and the back panels 32, FIGURE 2.

While the picture frame may be assembled in continuous steps from the flat, completely opened out blank represented in FIGURE 8, a particularly advantageous feature of the invention is that the frame units may be pre assembled to a stage at which they may remain flat for easy packing and shipping and yet be adaptable to speedy assembly without the necessity for adding glue or other adhesive materials to the various surfaces of each unit during its assembly. To provide for such pre-assembly, the first back panel 31 of each unit is provided with a crease or fold line 72 along its top face so that the strip of the panel between the fold lines 34 and 72 may be folded toward the body of the panel into a plane with the front panel 25. The fold lines 34 and 72 of the first back panel define between them a strip area 31a of the panel which,

together with a similar strip 25a of the front panel 25, is coated with a suitable self-sticking type adhesive which causes two surfaces so coated to adhere to each other while neither of the surfaces will adhere to a clean, uncoated surface which may be brought into contact with them. The panel sections 31a and 25a which are coated with the selfsticking adhesive are those panel sections which are brought together in laminated relationship in the final assembled frame unit as illustrated in FIGURE 2 to hold the concave contour of the front panels. In addition to providing the fold line 72 and the self-sticking adhesive along the panel sections 31a and 25a, the pre-assembled form of each of the frame units is further secured by permanently cementing the outside face of each reinforcing side panel 44 t0 the inside face of the side panel 30 and the front face of each tab 42 to the back face of the first back panel 31 over an area between the fold line 72 and the free edge surface 42a of the securing tab. To adapt the frame units to such pre-assembly, they must meet the following relative dimension requirements. The width of the front panel 25 as measured perpendicular to its fold lines plus the width of the first back panel strip portion 31a must be equal to the width of the first back panel strip 31 between its fold lines 72 and 45 plus the width of the reinforcing side panel 44 so that such portion of the panel 31 may be folded into the same plane with the panel 44 while in overlying or stacked relationship the front panel 25 is folded down flat on the panels 31 and 44 with the first back panel section 31a being folded into the same plane with the front panel 25 overlapping in flat relationship on the remaining portion of the first back panel 31. Stated otherwise, as in FIGURE 2, to achieve a substantially fiat relationship of the unit panels when secured together as above described the panels 44 and 30 are revolved clockwise about the fold line 45 into the plane with the first back panel 31 while the front panel 25 is folded downwardly with the first back panel section 31a being revolved clockwise about the fold line 72 so that the panel section 31a is in the plane with the front panel section 25 so that the panel section 31a and the panel 25 rest on the panel 31 between its fold lines 72 and 45 and the panel 44. Also, to achieve the folded relationship the distances between the fold lines 43 and 45 and 41 and must be equal while the width of the spacer strip and the spacer tabs 50 must be equal so that as the side panel 30 is folded clockwise with the panel 44 the spacer strip 40 and the tabs revolve clockwise about their back edges as the panel 31 between the fold lines 72 and 45 approaches the panel 32. The side panel 30 folds downwardly into the plane of the panel 32 and the spacer strip 40 and tabs fold flat.

From this pre-assembled substantially flat relationship each of the frame units may be brought to the fully assembled relationship illustrated in FIGURES 2, 7 and 9 by holding the second back panel 32, such as by setting the panel on a table top and lifting the laminated side panels 44 and 30 in a counterclockwise direction about the fold line 35 to bring the side panels 44 and 30 to a perpendic ular postion relative to the back panel during which motion the spacer strip 40 is similarly brought to perpendicular relationship with the back panel. The counterclockwise movement of these panels effects unfolding of the first back panel section 31a counterclockwise about its fold line 72 until the section 31a is in the same plane with the remaining portion of the first back panel 31 while the front panel 25 and the first back panel 3111 are brought to reverse folded relationship by folding the panels together as shown in FIGURE 2 along the fold line 34. The front and first back panels are pressed together along their sections 31a and 25a with the self-sticking adhesive on the facing surfaces of the sections adhering together to secure the panel sections into the laminated relationship illustrated and pull the front panel into the curved convex form. The ends of the frame units 21-24 are then folded together into the simulated mitred joint relationship shown in FIGURE 1 and the picture back panel is secured in the viewing window as previously described.

It will now be seen that a new and improved display device has been described and illustrated.

It will be further seen that a new and improved picture frame has been described and illustrated.

It will also be seen that the picture frame is formed of a light-weight flexible sheet material such as paperboard.

It will be further seen that the picture frame comprises a plurality of frame units interconnected with each other by simulated mitred joints thereby providing the pleasing appearance of a mitred joint while avoiding the difiicult problems adherent in the alignment of thin edge surfaces of sheet material required for a true mitred joint.

It will be further seen that the simulated joints are formed by a front panel of one frame unit overlapping the front panel of an adjoining connected frame unit of the top of the overlapping panel having an end edge cut along a line bisecting the angle between the frame units and fitting in close laminated or layer relationship on the overlapped front panel.

It will also be seen that the simulated joints between the frame units include end edge surfaces on the overlapped panels which engage the inside face of a side panel on the frame unit having the overlapping front panel to enhance the rigidity of the joint between the frame units and aid in holding them at the proper angle with each other.

It will be further seen that each picture frame embodying the invention includes a plurality of frame units each of which has a front panel, a side panel joined along a front edge with an outside edge of the front panel, a first back panel extending between the inside edge of the front panel and the side panel, and a second back panel spaced from and parallel to the first back panel, adjacent ends of the frame units having mating end edge surfaces providing a simulated mitred joint between the frame unit, one front panel extending in overlapping relationship on the adjacent front panel, the overlapping panel having an end edge surface formed at an angle providing the appearance of the mitred joint, and the overlapped end edge surfaces engaging inside surfaces of the overlapping frame unit for improving the structural rigidity of the simulated mitred joint and holding the joint frame unit sections at the proper angle relative to each other.

It will be further seen that the frame units in their disassembled state may be interconnected with each other along a fold line at adjacent ends of the side panels of the unit.

It will also be seen that the frame units may each be independently assembled and subsequently joined together to form the completed frame.

It will also be seen that a blank form adapted to be folded and cemented to provide the frame units of a picture frame embodying the invention has been described and illustrated.

It will be further seen that the blank picture frame form described and illustrated may be partially assembled to the stage at which it is folded substantially flat and may be subsequently unfolded and cemented in its assembled condition by adhering surfaces provided with a self-sticking adhesive which is applied to panels of the frame units prior to its partial assembly and folding to its flat readily storable condition.

It will also be seen that a preferred form of the picture frame includes concave front panels in which the end edge of each overlapping front panel has a convex curvature adapted to mate with the concave contour of the overlapped front panel and each front panel is cemented along an inside edge to a back panel to enhance the concave contour of the panel.

If desired, a modified frame a embodying the invention may comprise the structure illustrated in FIGURES 11 and 12. The modified frame units 21a and 22a of FIGURES l1 and 12 differ from the frame units 21 and 22 in the use of a laminated or layered relationship between the back panels instead of the spaced panel relationship thereby eliminating the spacer strip 40, the securing tab 42 and the tabs 50. Those panels of the frame units 21a and 22a which are identical in structure and function to the panels of the frame units 21 and 22 shall be designated by the same reference numerals as used in the description of the frame units 21 and 22. Each of the frame units 21a and 22a includes a front panel 25, a side panel 30, and first and second back panels 31 and 32, respectively. A blank for forming the frame units 21a and 22a is identical to that portion of the blank of FIGURE 8 defined between the fold lines 45 at the top of the blank and the fold lines 41 near the bottom of the blank thereby including in the blank the front, side, and two back panels 25, 30, 31, and 32, respectively, while excluding the reinforcing side panel 44, the tabs 50, the spacer strip 40 and the longitudinal securing tab 42. If desired, the blanks for forming the frame units 21a and 22a may be provided with self-sticking adhesive over the areas such as the areas 31a and 25a on either side of the fold line 34 so that when the front panel and first back panel 31 of each of the units are folded together in the vicinity of the fold line 34 the front and first back panels are secured together in lamination relationship over the longitudinal area provided with the self-sticking adhesive. Each of the frame units 21a and 22a is formed by folding their blank forms in substantially the same manner as in forming the frame units 21 and 22. The blank is creased along the fold line 34, 33, and 35. The back face of the first back panel 31 is secured to the front face of the second back panel with a suitable adhesive to interconnect the front and back panels in laminated relationship. The front panel is pressed against the back panels over the area covered by the selfsticking adhesive to secure the panels together along the fold line 34 for accentuating the concave contour of the front panel. After assembly of each of the frame units the completed frame is formed by interconnecting the end sections of the frame units to form simulated mitred joints by assembling the mating end sections of the units in the relationship shown in FIGURE 11. If the frame units are hinged together along the fold line 53 as previously discussed in connection with the frame shown in FIGURES 1-10, the adjacent frame units are folded together by rotating them about the fold line 53 toward each other with the front panel 25, back panel 31 of the unit 22a being inserted in underlapping relationship beneath the front panel of the unit 21a. The end edge surfaces 52 of the back panels 32 are brought together in mitred relationship as with the units 21 and 22. The end edges 60 and 61 on the front panel 25 and first back panel 31 of the unit 22a engage the inside face of the side panel 30 0f the unit 21a while the inside edges of the front and first back panel of the unit 22a along their fold line 34 engage the end edge surface of the first back panel 31 of the unit 21a. The end edge 54 on the front panel of the unit 21a overlies the front face of the front panel on the unit 22a providing a simulated mitred joint between the two units extending along a line dividing the angle of juncture between the units. If desired, a decorative reinforcing corner member 73 may be secured over the front face of the front panels 25 as shown in FIGURES 11 and 12.

Certain variations may be made in the frame units 21a and 22a. For example, the back panel 31 may be a separate piece from the other panels and secured to the front panel over the same area shown in FIGURE 12. Such a separate panel 31 has an inside edge aligned with the inside edge of the front panel along the line designated as the fold line 34 in FIGURE 12. Another modification in the frame units 21a and 22a includes the elimination of the back panel 32 and the addition of a reinforcing side panel 44 connected along its back edge to the outside edge of the back panel 31 and cemented to the side face of the side panel 30. Such a frame unit retains the cemented relationship between the front panel and the back panel 31 along the fold line 34 to preserve the cross-sectional shape illustrated.

The frame units 21a and 22a may, like the units 21 and 22, each be formed from a separate blank or they may be interconnected in a continuous strip comprising a plurality of frame unit blanks. As in the case of the picture frame 20 adjacent ends of the frame units comprising the frame 20a are adapted to mate with each other to pro vide simulated mitred corner joints. Whether the frame units are formed from a continous strip or separate blanks, each simulated mitred joint between units must include one overlapping front panel having an end edge out at an angle to bisect the angle between these joined frame units. While preferably each frame unit has one overlapping and one overlapped end it will be understood that units may be combined where half of the units have booth ends overlapping while the other half of the units have overlapped end sections. For example, in the frame 20, the units 21 and 23 may both have both ends with an overlapping front face while the intervening units 22 and 24 have both ends with end edges adapted to be overlapped so that each simulated mitred joint includes an overlapping and an overlapped front panel end section.

While the picture frames illustrated and discussed are rectangular it will be obvious that all other polygon shapes may be formed with the frame units. Other shapes will, of course, require angular relationships of the end surfaces of the unit panels which will provide the desired simulated mitred joints between the frame units. Also, the degree of curvature of the end edge of overlapping front convex and concave panels of the frame units are varied as the angle between joining frame units changes. Each of the various shapes of frames to which the invention is adaptable are made from blank either in continuous strips with the frame unit blanks interconnected along a fold line in the side panel and the free ends having mating end edges or, in the alternative, the several frame units may be constructed separately and subsequently joined as previously discussed.

The frames may be formed of paperboard or other similar flexible material. They may have a variety of surface finishes including those simulating a wood grain. Other decorative finishes include three-dimensional embossing. The cross-sectional configuration of each frame unit may be varied to provide other frame styles with compensating adjustments being made in the shapes of the end edges of the lapped and overlapping front panels to preserve the appearance of a mitred connection between the frame units while retaining the strength characteristics inherent in the extension of the end edges of the overlapped end section of each frame unit to the inside surface of the side panels of the overlapping adjacent end section.

It will now be seen that a modified form of picture frame embodying the invention includes first and second back panels cemented together in laminated or layered relationship and connected together by simulated mitred joints.

It will be further seen that the modified form of picture frame includes units having a front panel, a side panel connected along a front edge with the outside edge of the front panel, a first back panel secured along an inside edge with the inside edge of the front panel, a second back panel secured along an outside edge with a back edge of the side panel, and the first and second back panels being positioned in laminated relationship with each other.

It will be seen that a further modified form of picture frame unit includes a first back panel formed separately from the front panel to which it is secured in the assem bled form of the frame.

It will also be seen that a still further modified form of picture frame unit a single back panel is employed connected with the front panel.

It will be further seen that each form of picture frame embodying the invention may have a variety of front panel surface configurations, including convex, planar, and

10 others with the simulated mitred join-ts modified accordingly.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A picture frame comprising a plurality of joined frame units having adjoining inside edges defining a multisided viewing window, each of said frame units comprising a front panel having an inside edge defining one side of said viewing window, a side panel joined along a front edge thereof with an outside edge of said front panel, a back panel joined along an outside edge thereof with a back edge of said side panel and along an inside edge with said front panel, and each connection between adjacent frame units including one end section of one front panel overlapping on the front face of an end section of the other front panel, said overlapping front panel having an end edge extending along a line bisecting the angle of juncture between said adjoining frame units thereby providing from the front of said frame the appearance of a mitred joint between said adjacent overlapping front panels; and an additional back panel secured parallel to and spaced from said first mentioned back panel.

2. A picture frame comprising a plurality of frame units joined by simulated mitred joints, said frame units defining a viewing window, each of said frame units including a front panel having an inside longitudinal edge defining a side of said viewing window, a side panel connected along a front edge thereof with an outside edge of said front panel, a first back panel connected along an outside longitudinal edge with a back longitudinal edge of said side panel, a longitudinal spacer strip connected along a back edge to an inside edge of said first back panel, a second back panel connected along an inside edge with said inside edge of said front panel and extending to an inside face of said side panel substantially parallel with said first back panel and spaced apart therefrom, a reinforcing side panel secured along a back edge thereof with an outside edge of said second back panel and secured over an outside face thereof with the inside face of said side panel, a longitudinal securing tab secured along an inside edge with a front edge of said spacer strip and secured over a front face thereof to a back face of said second back panel for connecting said first and second back panels together in spaced relationship, said front panel being wider than the straight line distance between the front edge of said side panel and the inside edge of said second back panel whereby said front panel assumes a curved form when said frame units are assembled, each connection of adjacent ends of joined frame units including an end edge of said first and second back panels of a first of said frame units being formed at an angle with a longitudinal axis of said panels whereby said end edges of said panels engage the inside face of a side panel of a second of said joint frame units when said frame units are secured together for improving the structurel rigidity of said connection between said frame units, and the front panel of the second of said frame unit having an end section extending in overlapping rela tionship with the front panel of said first frame unit and having an end edge formed at an angle with the longitudinal axis of said front panel of said second frame unit to bisect the angle of juncture between said first and second frame units thereby providing a simulated mitred joint between said frame units.

3. A picture frame as defined in claim 2 wherein said front panels have concave front faces thereof and each said overlapping front panel has an end edge defining a convex curve mating with said concave front faces.

4. A picture frame as defined in claim 3 wherein a plurality of longitudinally spaced tabs are formed on said reinforcing side panels extending from the back end edge thereof substantially parallel to said longitudinal spacer strip for spacing the outside edges of said first and second back panels.

5. A picture frame as defined in claim 3 having frame units adapted to be converted between a partially assembled substantially fiat relationship between the components of said units and an assembled condititon, each of said units having said reinforcing side panel permanently cemented over an outside face to the inside face of the adjacent side panel, a portion of the front face of said longitudinal securing tab permanently cemented to the back face of said second back panel, and a self-sticking adhesive coating longitudinal areas of the front face of said second back panel and the back face of said front panel along the line of connection between said front panel and said second back panel.

6. A picture frame comprising a plurality of joined frame units defining a multi-sided viewing window, each of said frame units including a front panel having an inside edge defining one side of said viewing window, a side panel secured along a front edge thereof with an outside edge of said front panel, a first back panel secured along an inside edge thereof with said front panel adjacent the inside edge of said front panel and extending toward said side panel, a second back panel sesured along the outside edge thereof with said side panel along a back edge thereof, said second back panel being secured over the front face thereof with the back face of said first back panel thereby providing a laminated relationship between said first and second back panels, each connection between said frame units providing an overlapping relationship between the front panel on a first of said units and a front panel on a second of said units, the end edge of the overlapping front panel being formed at an angle with a longitudinal dimension of said panel extending along a line bisecting the angle of juncture between said frame units thereby providing a simulated mitred joint between said units, and the front panel of said second unit extending in underlapping relationship under said overlapping front panel and having an end edge formed at an angle with the longitudinal dimension of said panel whereby said end edge engages the inside face of the side panel of said first frame unit for improving the rigidity of said connection between said frame units.

7. A picture frame as defined in claim 6 wherein said front panel of each of said frame units are adapted to assume a concave contour when said units are in assembled relationship and the end edge of said overlapping front face of each of said first frame units defines a convex curve to provide a smooth joint with said overlapped front face of said second frame unit.

8. A picture frame as defined in claim 7 wherein each of said front panels of said frame units are secured over an area of the back face thereof along the inside edge thereof with a front face of one of said back panels for holding each said front panel in its concave relationship.

9. A substantially flat flexible sheet form adapted to be assembled into a picture frame, said form including a section adapted to be assembled to form each side frame unit of said frame, each said section including a front panel, a side panel hingedly secured with said front panel along a fold line, a back panel hingedly secured with said side panel along a fold line, the end edges of adjacent ends of said frame unit sections being formed at angles to provide overlapping relationship between said front panels of said units when said units are in assembled relationship whereby a simulated mitred joint is formed, said adjacent ends of said frame unit sections being joined along a fold line between ends of said side panels, the end edge of one end of said front panels being formed at an angle on said panel providing an end section on said panel adapted to overlap the end section of the front panel of the adjoining frame unit section when in assembled relationship and said end edge extending along a line bisecting the angle of juncture between joined end sections of said frame units when said units are assembled.

10. A sheet form for forming a picture frame as defined in claim 9 including in addititon a second back panel secured along a fold line with the other longitudinal edge of said front panel, a reinforcing inside side panel hingedly secured along a fold line with said second back panel, a longitudinal spacer strip hingedly secured along a fold line with the other edge of said first back panel and a longitudinal securing strip hingedly secured along a fold line with said longitudinal spacer strip.

References Cited UNITED STATES PATENTS 1,223,409 4/1917 McMillan 40155 2,762,148 9/1956 Alcaraz 40155 3,286,387 11/1966 Poertner 40-154 EUGENE R. CAPOZIO, Primary Examiner.

W. J. CONTRERAS, Assistant Examiner. 

